The invention relates to heat transfer devices and more particularly to a heat transfer device particularly suited for use as an evaporator plate in a diffusion cloud chamber.
Studies of cloud condensation nuclei require that precisely controlled supersaturated environments, between 100 percent and 103 percent relative humidity, be maintained when employing diffusion cloud chambers. Unfortunately, diffusion chambers used to provide such an environment are characterized by two stringent requirements. The first being that thermally active surfaces must be precisely and uniformly controlled to a tolerance of .+-. 0.1.degree. C. or better. The second requirement being that the thermally active surfaces be uniformly wetted.
In order to achieve the necessary thermal control, present systems are characterized by high flow fluids or extended area thermoelectric control systems. As can be appreciated, such systems are bulky, slow in response time, and generally inefficient in power usage. Moreover, the usual approach of using multiple heat pipes with metal to metal heat transfer regions does not adequately provide the necessary temperature uniformity over the extended surfaces.
In order to achieve uniformly water wetted surfaces, it currently is common practice to deposit filter paper on these surfaces and employ the paper as a wick. However, it has been found that, in practice, it is very difficult to assure that uniform wetting will be experienced under all operating conditions.
Therefore, there currently exists a need for a practical heat transfer device which can readily be employed as an evaporator plate in a diffusion cloud chamber in order to overcome the aforementioned difficulties and disadvantages.
It is, therefore, a general purpose of the instant invention to provide an improved internally supported heat transfer device which includes thermally active surfaces particularly adapted to be reliably and uniformly wetted under substantially all operating conditions while the temperatures thereof are precisely and uniformly controlled to facilitate the maintenance of temperature uniformity over the external surfaces of this device.